Explosive switch



April 5, 1960 A. B. LEAMAN ExPLosIvE swITcr-x INVENTOR A. B. LEAMAN L. @@M 19M. l WA n. LN w A B 3 2a N nvr-SSB 9 n@ ATTORNEYS United States Patent O EXPLOSIVE SWITCH Audley B. Leaman, Chevy Chase, Md., assiguor to the United States of America as represented by the Secretary of the Navy Application October 8, 1953, Serial No. 385,039

'3 Claims. (Cl. 200-142) (Granted under Title 35, U.S. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

The present invention relates to a switch and more particularly to a new and improved explosive operated switch for interrupting an initially closed circuit and for closing an initially open circuit as the switch is operated in response to an explosive pressure generated therein.

Explosive operated switches heretofore employed, particularly in ordnance missiles, have not proven to be entirely satisfactory under all conditions of service for the reason that such devices failed to withstand the severe shocks to which they were subjected, particularly during transportation, launching and firing as the case may be and also for the reason that such devices required an electrical firing impulse of a relatively high degree to cause the switch to operate and oftentimes as the explosive charge within the switch casing is fired, the pressure developed therefrom would cause the casing to be shattered and thus causing switch failure.

In the device of the present invention the aforesaid diculties have been overcome by providing a normally locked explosive switch constructed and arranged to withstand a sudden and severe shock without damage thereto and in which means are provided for operating the switch from an initial position to a moved position as the explosive charge therein is fired, the explosive pressure being sutlicient to operate the switch, however, insuicient to damage the switch casing.

Furthermore, the invention contemplates the provision of a new and improved normally locked explosive switch wherein means responsive to an explosive force operates the switch from an initial position to a moved position whereupon an initially closed control circuit may be opened and an initially opened control circuit may be closed. While the device of the present invention is particularly adapted for use in an ordnance missile such, for example, as a rocket, bomb, submarine mine or depth charge, it may be advantageously used with any type of electrical apparatus for controlling a plurality of electrical circuits.

An object of the present invention is to provide a new and improved switch wherein means responsive to an explosive pressure generated within the switch casing operates the switch from an initial closed position to a moved closed position.

Another object of the invention is the provision of an explosive switch wherein a normally locked plunger actuated in response to an explosive pressure operates the switch to interrupt one control circuit and complete another control circuit.

A further object of the invention is the provision of an explosive switch wherein a pressure responsive element maintains one pair of switch contacts in an initial closed position and actuates a second pair of initial open contacts to a closed position as the pressure responsive 2,931,874 Patented Apr. 5, 1960 detailed description when considered in connection with' the accompanying drawings wherein:

Fig. 1 is a central longitudinal sectional view of the explosive switch in accordance with the present invention with the component parts thereof in an initial position;

Fig. 2 is a fragmentary sectional view taken on the line 2-2 of Fig. 1;

Fig. 3 is a fragmentary sectional view similar to Fig. 2 with the switch actuating element in a moved position; and

Fig. 4 is a cross sectional view taken on the line 4-4 of Fig. 1.

Referring now to the drawing and more particularly to Fig. 1 thereof, the numeral 10 generally indicates the explosive switch of the present invention comprising a casing 11 composed of any material suitable for the purpose such, for an example, as brass or the like. A sleeve 12 composed preferably of brass is disposed within a bore or recess 13 formed in the casing 11, having one end thereof in abutting engagement with a shoulder 14 arranged on the casing, the other end thereof terminating in an annular conical portion 15.

Disposed within the recess 13 and maintained therein by a ange 16 formed by crimping the end portion of the casing 11 into abutting engagement therewith is a closure or cap 17. The cap is composed of suitable plastic such, for example, as nylon, and provided with an annular conical portion 18 similar to the portion 15 and a pair of mutually spaced openings or bores 19 formed therein. It will be noted in Fig. 1 that a sealing gasket 21 is disposed between the conical portions 15 and 18 and in sealing engagement with the casing and detonator.

An electroresponsive detonator 22 is arranged within the sleeve 12 and cap 17, one end of the detonator being in engagement with a shoulder 23 formed in the sleeve and the other end thereof being in sealing engagement with a washer 24 composed of felt and disposed between the detonator and cap. It will be apparent, however, that as the detonator 22 and felt washer 24 are inserted into the recess 13 and the end of the casing crimped as shown, the felt washer is compressed into sealing engagement with the detonator and cap, the conical portions 15 and 18 on the sleeve and cap are moved into sealing engagement with the pair of V-shaped grooves 25 respectively, formed on the gasket 21, whereupon the gasket is moved into sealing engagement with the detonator. Thus by this arrangement, a leakproof connection is maintained between the aforesaid elements thereby to prevent escape of gas pressure from explosion chamber 26 as the detonator is red in response to an electrical impulse received thereby. The iring connection to the detonator is established by way of a pair of mutually spaced terminals 27 connected to the detonator in the conventional manner and extending through the openings 19 formed in the cap and terminating a predetermined distance therebeyond.

The bore 13 communicates with a bore 28 somewhat smaller in diameter than the bore 13. A seat 29 is formed at one end of the bore 28 and a seat 31 is formed substantially at the other end thereof, Fig. l.

An actuating plunger generally indicated by the reference character 32 is releasably locked within the bore 28 and comprises a shaft 33 composed of any material suitable for the purpose such, for example, as beryllium copper, the plunger being adapted to be released and operated slidably from an initial position to a moved position in response to a predetermined pressure applied thereto. The shaft 33 has formed on one end thereof a ared head 34, the other end thereof having formed thereon a contact element 35. As shown more clearly in Fig. l, the shaft 33 and flared head is enclosed in a casing composed of any suitable insulating material comprising a tubular member 36 applied to the shaft 33 and a flared portion 37 applied to the head 34, the aforesaid insulating casing being applied to the shaft and head in any conventional manner, preferably by a suitable molding operation.

It will be noted that the plunger 32, Fig. l, is locked in an initial position by a locking member generally indicated by the numeral 38 composed of suitable ductile material such, for example, as aluminum. The member 38 is secured to the flared portion 37 of the plunger by a flange 39 formed thereon and crimped into engagement with the flared portion. The element 38 is provided with a conical member 41, Fig. l, integral therewith in sealing engagement with the seat 29 and constructed and arranged to yield in response to a predetermined pressure applied thereto, the conical member being maintained in sealing engagement with the seat 29 by the aforesaid brass sleeve 12. Furthermore, by the aforesaid conical member and seat arrangement the plunger 32 is normally locked to the casing in an initial position. While the angle of the conical element 41 is shown to be substantially 30, it will be understood that this angle may be varied as desired to effect locking engagement between the element and the casing whereupon the element may be actuated by a greater or lesser pressure as the case may be.

Disposed within a well or recess 42 formed in the casing 11 is a contact assembly generally indicated by the reference character 43. The assembly comprises a pair of supports 44-45 enclosed w1thin a sleeve or casing 46 and a pair of normally closed contacts 47 mounted in support 45 and a pair of normally open contacts 48 mounted in the support 45, the aforesaid support and sleeve being composed of any suitable insulating material such, for example, as nylon. The contact assembly 43 is disposed between a washer 49 and a cap or closure 51 composed of suitable insulating material and maintained within the recess 42 by a flange 52 formed on the casing 11 and crimped into abutting engagement with the cap 51. Furthermore, by the aforesaid cap, washer and sleeve arrangement the contacts 47 and 48 are adequately insulated from the casing 11.

The support 44 is provided with a centrally disposed bore 53 extending therethrough in registration with a bore 54 formed in the support 45 thereby to permit the plunger 32 to be actuated from an initial position to a moved position, Fig. 3, as the detonator 22 is tired.

Each contact 47 is disposed within matching grooves 55 formed on the supports 44-45 with one end thereof extending through an opening 56 formed in the cap 51 and terminating beyond the cap. The other end of each contact 47 is provided with a bight portion 57 which terminates in a yieldable element 58 disposed within grooves 50 in engagement with the contact or bridging member 35. Each contact 48 is provided with a yieldable member 59 disposed within the bore 54, having a semicircular contact element 61 formed thereon, Fig. 4. One end of each yieldable member extends through an opening 62 formed in the cap 51, the other end thereof, being provided with a bight portion 63, the terminal portions 64 thereof being disposed within a groove 65 formed in the support 45, Fig. 3.

lt will be noted in Fig. 1 that the contact member 35 is serrated as at 66. Furthermore, the contact member 35 is composed of hard conductive material while the contacts 47 and 48 are composed of relatively soft or ductile conductive material. Thus by this arrangement, the serrations on member 35 will tend to bite into the soft material of contacts 47 and 48 in such a manner as to establish an exceptionally good electrical connection therebetween.

It will be noted in Fig. l that the plunger 32 is normally locked to the switch casing by the conical ductile member 41 disposed within and in sealing engagement with the seat 29 formed thereon whereupon an electrical connection is established through the contact member 35 and the contacts 47 and a control circuit is rendered effective until the detonator 22 is fired in response to a low order of electrical energy supplied thereto from a suitable source of power such, for example, as a charged condenser included in the control circuit. When the detonator is fired a sufficient amount of gas pressure is generated within the sealed chamber 26 and applied to the conical ductile member to cause release of the conical member from the seat 29 and forcibly move the plunger 32 a predetermined amount. When this occurs, the ange 39 on the ductile member 38 is forcibly driven into engagement with the seat 31 and the conical member thereon is forcibly driven into engagement with the wall defining the bore 28 with sufcient force to lock the plunger to the casing with the contact member 35 in engagement with contacts 48 of Fig. 3. Thus an electrical connection is established through the contact member 35 and the contacts 48 and a control circuit is rendered effective, however, the contacts 47 are now open whereupon the control circuit thereof is interrupted.

From the foregoing, it will be apparent that a new and improved normally locked explosive switch has been devised wherein means responsive to a predetermined pressure generated within a sealed chamber operates the switch from an initial position to a moved position whereupon an initially closed circuit may be open and an initially open circuit may be closed.

Whereas, the invention has been described in detail in connection with an explosive operated switch particularly adapted for use in an ordnance missile, it will be understood that it may be employed, if desired, in similar electrical circuit arrangements for interrupting an initially closed circuit for closing an initially open circuit as the switch is operated from a normally locked position to a subsequent lock position.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. In a switch of the character disclosed, a sealed casing having a conical surface formed therein, a pair of normally closed contacts and a different pair of normally open contacts carried interiorly by said casing and insulated therefrom, movable means initially locked to said casing for opening said normally closed contacts and for closing said normally open contacts, an enlarged head on said movable means, a yieldable conical member secured to said head and in engagement with said conical surface for locking the movable means to the casing in an initial position until the yieldable member has been disengaged from said surface, said movable means being released and moved from said initial position to a final position in response to a predetermined explosive pressure generated within said casing suicient to deform and disengage the conical member from said conical surface, and explosive means arranged within said casing and fired in response to an electrical impulse received thereby for generating said pressure within the casing.

2. In a switch of the character disclosed, a sealed casing having a conical surface formed therein, a pair of normally closed contacts carried interiorly by said casing, a diiferent pair of normally open contacts carried interiorly by said casing in spaced relation with respect to said normally closed contacts, a plunger releasably locked within the casing and movable from an initial locked position to a final position when released, means on said plunger for maintaining the normally closed contacts closed only while the plunger is locked in said initial position and for closing said normally open contacts as the plunger is actuated to said final position, a yieldable conical member mounted on said plunger in sealing engagement with the said conical surface of the casing for releasably locking the plunger to the casing in said initial locked position until the conical member has yielded suddenly in response to a predetermined explosive pressure applied thereto sufliciently to be disengaged from said conical surface, and explosive means sealed within said casing and red in response to an electrical impulse for applying said pressure to said conical member.

3. An explosive actuated switch comprising a sealed casing having a conical surface formed therein, a pair of normally closed contacts carried interiorly by said casing, a different pair of normally open contacts carried interiorly by the casing in spaced relation with respect to said normally closed contacts, means for supporting and insulating said contacts from the casing, a plunger slidably and releasably arranged within said casing and movable from an initial locked position to a nal position when released, a yieldable conical head on said plunger normally in engagement with said conical surface for maintaining the plunger in said initial locked position until a predetermined explosive pressure has been applied thereto sufficient to disengage said conical head from said conical surface, an electroresponsive detonator red in response to an electrical impulse for applying said pressure to said conical head, and means on the plunger and insulated from the casing for maintaining the normally closed contacts closed only while the plunger is in said initial locked position and for closing said normally open contacts as the plunger is actuated to said nal position.

References Cited in the file of this patent UNITED STATES PATENTS 2,522,596 Bevins Sept. 19, 1950 2,721,240 Filbert Oct. 18, 1955 2,816,196 Daudelin Dec. 10, 1957 

